A wide variety of physical methods for delivery of drugs (or other materials) to biological cells are known, including injection, electroporation, sonophoresis, etc. Electroporation, which entails the formation of self-healing pores in a cellular membrane, is of considerable interest. A major reason for this interest is that electroporation tends to be more effective than chemical delivery methods. Accordingly, many variants of electroporation have been investigated, including combined use of sonophoresis and electroporation.
Physical approaches such as electroporation for delivery of naked DNA represent a promising and rapidly expanding field. “Molecular delivery” to cells using physical methods encompasses delivery of DNA, RNA, siRNA, oligonucleotides, proteins, as well as small molecules such as drugs or dyes. Electroporation has won wide support as a tool for DNA transfer and is the preferred non-viral method for many applications. In most protocols, cells are suspended in a cuvette, exposed to a train of electric pulses using plate electrodes to achieve a uniform electric field, and then returned to culture. The major advantage of electroporation is that it is, in theory, effective for nearly all cell types. Despite these advantages, high rates of cell death and difficulty with in situ methods remain problems for many applications. Accordingly, there is a need in the art to develop novel methods for transfer of DNA and other small molecules into biological cells.